本研究利用固相反应法合成了一系列镧取代La_xSr_2-3x/2Fe_1.5Ni_0.1Mo_0.4O_6-δ (La_xSFNM, x=0, 0.1, 0.2, 0.3, 0.4)钙钛矿陶瓷材料, 并研究其作为固体氧化物燃料电池阳极的电化学性能。X射线衍射(XRD)测试表明合成的粉末具有立方钙钛矿结构。在高温下利用氢气还原La_xSFNM样品, 发现其晶粒表面析出纳米尺度的Fe-Ni合金颗粒, 并且偏析纳米颗粒的密度随着La ³⁺掺杂量的增加而显著降低。在对称电池阻抗测试中, 随着La ³⁺掺杂量的增加, 阳极极化阻抗逐渐降低, 掺入量为0.3时阻抗达到最小值。La_0.3SFNM对称电池在750 ℃下极化阻抗仅为0.16 W·cm ², 进一步增加掺杂量时, La_0.4SFNM对称电池极化阻抗增加至0.17 W·cm ²。La_0.3SFNM材料良好的电极反应催化活性源于适当分布的Fe-Ni合金纳米偏析颗粒与La_xSFNM陶瓷基体的共同作用。利用流延法制备一系列以La_xSFNM为阳极、SmBa_0.5Sr_0.5Co₂O₆为阴极、LSGM为电解质的单电池, 使用氢气作为燃料时, La ³⁺掺杂量x=0.3的单电池表现出最高的功率密度, 在750、650和550 ℃时峰值功率密度可达1.26、0.90和0.52 W·cm ^-2。上述结果表明, La_0.3Sr_1.55Fe_1.5Ni_0.1Mo_0.4O_6-δ可以用作高性能SOFC阳极催化剂。

Lanthanum-substituted La_xSr_2-3x/2Fe_1.5Ni_0.1Mo_0.4O_6-δ (La_xSFNM, x=0, 0.1, 0.2, 0.3, 0.4) oxides were synthesized by the solid-state reaction method, and investigated as potential anodes for Solid Oxide Fuel Cells(SOFC). X-ray diffraction patterns of as-synthesized powders confirm the formation of the cubic perovskite structure. Reduction in H₂ promotes the segregation of nano-scale metallic Fe-Ni alloy particles on the grain surfaces. Scanning electron microscopy observations indicate that increasing La ³⁺ dopants results in a decrease in the density of the exsolved nanoparticulates. Based upon impedance measurements on symmetrical fuel cells, the anode polarization resistance decreases with the La ³⁺ dopant increasing, and attains a minimal value of 0.16 W·cm ² for La_0.3SFNM at 750 ℃, followed by a slight increase to 0.17 W·cm ² for La_0.4SFNM. The highest catalytic activity of La_0.3SFNM toward electro- oxidation of hydrogen fuels could be ascribed to the synergy between the exsolved Fe-Ni alloy nanoparticulates and the supporting La_xSFNM oxides. Thin La_0.9Sr_0.1Ga_0.8Mg_0.2O₃ (LSGM) electrolyte fuel cells with La_0.3SFNM anodes and SmBa_0.5Sr_0.5Co₂O₆ cathodes exhibit the highest power densities, e.g., 1.26, 0.90 and 0.52 W·cm ^-2 at 750, 650 and 550 ℃, respectively. These results demonstrate La_0.3SFNM oxide as a promising high performance SOFC anode.